WO2018184324A1

WO2018184324A1 - Light source system and projection device

Info

Publication number: WO2018184324A1
Application number: PCT/CN2017/094797
Authority: WO
Inventors: 郭祖强; 杜鹏; 李屹
Original assignee: 深圳市光峰光电技术有限公司
Priority date: 2017-04-07
Filing date: 2017-07-28
Publication date: 2018-10-11
Also published as: CN108693688B; CN108693688A

Abstract

A light source system, comprising a light source (401), used for emitting multiple mutually parallel light beams; a light homogenising device (403), used for adjusting the uniformity of the light source, the light homogenising device (403) being a double row micro-lens array, and the source light avoiding a recessed area on the double row micro-lens array; and a relay module (404), used for converging the beam and imaging. Also provided is a projection device.

Description

Light source system and projection equipment

Technical field

The present invention relates to the field of optics, and more particularly to a light source system and a projection apparatus for a laser light source.

Background technique

At present, the homogenizing device for the laser light source mainly has a square rod and a compound eye. The square bar is divided into a solid square bar and a hollow square bar. The principle is to use the light to totally or internally reflect the inside of the square bar to homogenize. The number of reflections of the light in the square bar determines the final spot uniformity. The length of the rod is longer to ensure the number of reflections, increasing the optical path and volume of the optical system. In contrast, the use of a double compound eye, a double row microlens array, as a light homogenizing device can reduce the volume of the system.

According to the uniform light principle of the double compound eyes, as shown in FIG. 1, the Gaussian distribution laser light is incident on the surface of the first row of lens arrays, and is divided into a plurality of small spot units whose size h is the same as the outer shape of the microlens. In the double compound eye, the thickness l is the focal length f of the microlens unit. Therefore, the spot on the surface of the first row of compound eyes is on the focal plane of the second row of compound eyes, and each spot unit on the first row of compound eyes passes through the second row. After the compound eye is superimposed, the image is formed by the relay system. Let the focal length of the relay system be f', and the image height on the image plane be h'. According to the imaging relationship, there are:

For projection systems, the image height h' is usually required to be small due to the limitation of the amount of expansion of the entire optical system. In addition, the diameter of a single laser beam incident on the surface of the compound eye is between 1 mm and 3.5 mm, and it is necessary to ensure that the number of splitting units of the first row of the plurality of laser beams is 15 or more, thereby avoiding serious diffraction effects, and thus the microlens. The size of the outer shape is large. Ultimately, the double compound eyes need to be thicker to achieve a larger f.

The requirement of compound eye thickness will bring certain difficulties to the processing of compound eyes. Since the power of the laser is large and the energy is concentrated, the compound eye homogenizing device used must use quartz glass material, and the ordinary plastic material is easily damaged under the irradiation of the laser. The process for making quartz glass compound eyes includes lithography processing, mechanical processing, laser processing, bonding, and the like. However, the use of the above process to make quartz glass compound eyes is extremely expensive, and ordinary machining cannot meet the accuracy requirements. There is also a method for preparing a compound eye homogenizing device by a sol-gel method, which requires a compound eye body which is more than twice as large as the mother eye, and the mother body is usually a compound eye of a plastic material, which is low in cost and high in efficiency; If this method is used to make a double compound eye with a large thickness requirement, a depressed area will appear in the center of the prepared quartz glass double compound eye. Such a compound eye with a concave center causes deformation of the imaging spot and uneven illumination distribution, and thus cannot satisfy the user's needs.

Therefore, it is necessary to provide a new light source system and projection apparatus to solve the above problems.

Summary of the invention

The technical problem to be solved by the present invention is to provide a light source system and a projection device, which are not only low in cost, high in efficiency, but also uniform in illumination and have a good user experience.

In order to solve the above technical problem, a technical solution adopted by the present invention is to provide a light source system, the light source system comprising:

a light source for emitting source light, the source light comprising a plurality of beams parallel to each other;

a light homogenizing device, the source light is incident on a light homogenizing device for adjusting uniformity of source light, the light homogenizing device is a double row microlens array, and a lens surface of the double row microlens array The center has a recessed area, the plurality of beams avoiding the recessed area on the double-row microlens array;

A relay module for concentrating and imaging the light beam.

Wherein, the distance between the two beams of the plurality of beams of the source light is greater than the maximum diameter of the recessed region.

Wherein the light source system further comprises a compression system on the optical path between the light source and the light homogenizing device for reducing the diameter of the source light. Wherein the compression system uniformly reduces the distance between the beams.

Wherein the compression system includes at least one positive lens adjacent to the light source and at least one negative lens adjacent to the light homogenizing device, the positive lens for concentrating each of the light beams, and the negative lens for collimating each The light beam.

Wherein the main optical axes of the positive lens and the negative lens coincide, and the focal points of the positive lens and the negative lens adjacent to the side of the light homogenizing device coincide.

Wherein the compression system is adapted to change the optical path of the peripheral beam of the source light such that the distance between the peripheral beam of the source and the inner beam of the source is reduced in a first direction perpendicular to the central axis of the source.

Wherein, the compression system is further configured to change the optical path of the peripheral beam of the source light such that the distance between the peripheral beam of the source and the inner beam of the source is reduced in a second direction perpendicular to the central axis of the source.

Wherein, the compression system includes two sets of first reflecting means disposed opposite each other in a first direction on both sides of the central axis of the source light, and the source light is reduced by the reflection of the first reflecting means to reduce the source light in the first The diameter in one direction.

The compression system includes two sets of second reflecting devices disposed opposite to each other in a second direction on both sides of the central axis of the source light, and the source light is reduced by the reflection of the second reflecting device to reduce the source light. The diameter in the two directions.

Wherein the distance between the two beams of the plurality of beams of the source light is smaller than the maximum diameter of the recessed region.

Wherein the light source system further includes an expansion system on an optical path between the light source and the light homogenizing device for changing an optical path of the inner circumference beam of the source light such that the inner circumference beam of the source light passes through The expansion system expands toward the peripheral beam of the light source, avoiding the recessed regions of the light homogenizing device.

Wherein, the recessed area has a diameter of 2 mm to 4 mm.

Wherein, the light homogenizing device is processed by a sol-gel process.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide a projection apparatus including the light source system of any of the foregoing.

The invention has the beneficial effects that the present invention provides a light source system and a projection device. The light source system comprises: a light source, a light homogenizing device and a relay module, wherein the light source is used for emission and is parallel to each other. The source light of the plurality of beams, the homogenizing device is a double-row microlens array, the lens surface center of the double-row microlens array has a recessed area, and the plurality of beams avoid the double-row microlens array The recessed area solves the technical problem of uneven illumination of the spot deformation in the prior art. Not only low cost, high efficiency, but also uniform illumination, good User experience.

DRAWINGS

1 is a schematic diagram of a uniform light of a double compound eye in the prior art;

2 is a schematic structural view of a first embodiment of a light source system of the present invention;

Figure 3 is a schematic view of the light spot of the structure shown in Figure 2 on the light homogenizing device;

4 is a schematic structural view of a second embodiment of a light source system of the present invention;

Figure 5 is a schematic view of the light spot of the structure shown in Figure 4 on the light homogenizing device;

6 is a schematic structural view of a third embodiment of a light source system of the present invention;

7 is a schematic view of an optical path in a third embodiment of the light source system of the present invention;

Figure 8 is a schematic illustration of the spot of the structure of Figure 6 on a light homogenizing device.

detailed description

It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Embodiment 1

Please refer to FIG. 2 , which is a schematic structural diagram of a light source system according to a first embodiment of the present invention. As shown in FIG. 2, the light source system of this embodiment includes a light source 401, a compression system 402, a light homogenizing device 403, a relay module 404, and an image plane 405.

Wherein, the light source 401 is used to emit source light, wherein the source light comprises a plurality of light beams parallel to each other. The light source of this embodiment is a laser light source that emits a plurality of laser beams. The image plane 405 is coated with a phosphor, and the laser source light from the light source is imaged at the image plane 405 by the light source system of the present invention. The phosphor is excited to emit light. The center of the light homogenizing device 403 has a recessed area having a diameter of 2 mm to 4 mm, and a plurality of light beams avoid the recessed area. In the present embodiment, the distance between the two beams of the plurality of beams of the source light is greater than the maximum diameter of the recessed region. The relay module 404 is a collecting lens, specifically a convex lens in the present embodiment, for collecting light onto the image plane 405 for imaging. In other optional embodiments, a plurality of lenses that function as a converging function may be implemented as long as they can function as a converging light to image plane imaging.

The compression system 402 is located on the optical path of the laser beam to reduce the diameter of the source light, reduce the distance between different laser beams, and also reduce the length of the system. The light homogenizing device 403 is used to adjust the uniformity of the light beam. In the present embodiment, the light homogenizing device 403 is a double-row microlens array whose surface is composed of a plurality of matrix-arranged microlens units. Wherein, the focal length of each lens unit is the same, the second row array is on the focal plane of the first row of lenses, and the second row array is identical to the first row array and the lens units are in one-to-one correspondence. Specifically, the shape of the microlens is rectangular or hexagonal.

When the respective beams of the source light are incident on the light homogenizing device 403, first, when the laser beam is incident on the first row of arrays, it is divided into a plurality of small regions, and the uniformity of the spot is good in each small region, and the second row array is better. The spots of each region in the first row of arrays are superimposed and imaged by subsequent optical systems, and the uniformity of imaging is the superposition and complementarity of the uniformity of each region of the first row, so that better uniformity can be obtained.

Among them, the double-row microlens array is made by a sol-gel process, in particular, quartz glass powder is used as a solute dissolved in a solvent and injected into a mold. Hydrolysis is carried out under the action of a catalyst, a condensation reaction takes place, and a stable transparent sol system is formed. The sol is further aged to form a gel, and the gel is dried and dehydrated to finally form a microlens array assembly. This The double-row microlens array prepared by the method has low cost and high efficiency, but shrinkage occurs on the surface of the central area, and a certain depression is formed, and FIG. 3 is specifically referred to. In the present embodiment, since the source light is first compressed by the compression system 402, the source light diameter is greatly reduced, about 1.5 mm, and the distance between the light beams is reduced to about 3 mm, and the system length is reduced, so that The recessed area in the center of the double compound eye can be avoided. Referring to FIG. 3, the compression system of the present invention uniformly reduces the distance between the beams, and the laser beam is effectively compressed to avoid the central shrinkage region after being compressed by the compression system 402, thereby avoiding the uneven illumination and affecting the use. effect. Due to the sol-gel method, the cost of the product is also greatly reduced, and the production efficiency is improved.

Specifically, in the present embodiment, the compression system 402 includes a positive lens and a negative lens, wherein the main optical axes of the positive lens and the negative lens are disposed in a coincident manner, and the positive lens and the negative lens are adjacent to the side of the light homogenizing device. The focus is coincident, and the positive lens is located in front of the main optical axis, that is, the positive lens is disposed adjacent to the compression system 402, the negative lens is disposed adjacent to the light homogenizing device 403, and the positive lens and the negative lens are adjacent to the side of the light homogenizing device The focus is coincident. Wherein, the positive lens is a convex lens for concentrating each of the light beams, and the negative lens is a concave lens for collimating each of the light beams. After the mutually parallel laser beams enter the compression system 402, they are first concentrated by a positive lens, and then passed through a negative lens to cause the outgoing light path to be emitted parallel to the incident optical path. Thus, the direction of the beam after passing through the compression system 402 is unchanged, but the distance between the beams is reduced, so that the beam can avoid the central constriction of the homogenizing device 403. The above is only an optimal embodiment. In practice, the compression system 402 may also be a combination of a plurality of convex lenses and a plurality of concave lenses, and can be implemented as long as the above functions can be realized.

Embodiment 2

4 and 5, the present embodiment is substantially the same as the previous embodiment, and the light source system includes a light source 601, a compression system 602, a light homogenizing device 603, a relay module 604, and an image plane 605.

The difference is that the structure of the compression system 602 is different. Since the source light is composed of a plurality of beams parallel to each other, it has an inner circumference light beam near the center of the light source and a peripheral light beam away from the center of the light source. As shown in FIG. 4, the direction of the vertical source light beam includes a first direction parallel to the plane of view of FIG. 4 and a second direction perpendicular to the plane of view of FIG. In this embodiment, the compression system changes the optical path of the peripheral beam of the source light to reduce the distance between the peripheral beam and the inner beam in a first direction perpendicular to the central axis of the source. Specifically, the compression system 602 includes two sets of first reflecting devices disposed opposite to each other in a first direction on both sides of the central axis of the source light, and the two sets of first reflecting devices respectively compress the light beam in the first direction toward the main optical axis, so that The direction of the beam after compression system 602 is unchanged, but the distance between the peripheral beam and the inner beam is reduced, making it possible to avoid the central constriction of the homogenizing device 603.

Specifically, in the present embodiment, each set of first reflecting means comprises two parallel and oppositely disposed mirrors. After the beam is reflected twice, the direction of the optical path does not change, but is concentrated toward the main optical axis of the source light. At this time, the spot formed on the light homogenizing device 603 is as shown in FIG. 5, effectively avoiding the center shrunken area. Of course, in other alternative embodiments, more than two mirrors may be provided, which can be implemented as long as the above functions can be achieved.

Embodiment 3

Referring to Figures 6 and 7, the present embodiment is further improved on the basis of the above two embodiments. Referring to Figures 6 and 7, improved on the basis of the second embodiment The example is explained, in fact, it is also possible to improve on the basis of the first embodiment.

The light source system includes a light source 801, a compression system 802, a light homogenizing device 803, a relay module 804, and an image plane 805.

On the basis of the above embodiments, further, the compression system further includes two sets of second reflecting means disposed opposite to each other in the second direction on both sides of the source light central axis near the light homogenizing device for performing secondary compression on the light beam. Changing the optical path of the peripheral beam such that the distance between the peripheral beam and the inner beam of the light source is reduced in the second direction, and the source light is reduced in the second direction by the reflection of the second reflecting means diameter of. The second reflecting device is similar in structure to the first reflecting device, and may be a mirror or two or more mirrors, which can be implemented as long as the above functions can be realized. Specifically, in the present embodiment, a first mirror and a second mirror constituting the first reflecting means and a third mirror and a fourth mirror constituting the second reflecting means are included. Referring to FIG. 7, taking the path of one of the beams as an example, the beam is sequentially reflected by the first mirror, the second mirror, the third mirror, and the fourth mirror. The Y axis is used as the main optical axis of the source light. Wherein the first mirror and the second mirror are perpendicular to the XY plane, and the third mirror and the fourth mirror are perpendicular to the YZ plane. The four-sided mirrors are all at a 45 degree angle to the incident light but are not limited to a 45 degree angle setting. The first mirror and the second mirror reduce the distance of the beam from the optical axis in the X direction, and the third mirror and the fourth mirror reduce the distance of the beam from the optical axis in the Z direction. Thereby the surrounding beams are brought closer to the optical axis. The spot formed by it is shown in Fig. 8, so that the light beam further avoids the central shrinkage zone of the light homogenizing device 803 to ensure the reliability of the product.

Embodiment 4

This embodiment is substantially the same as the above-described embodiment, except that in the present embodiment, the distance between the two beams of the plurality of beams of the source light is smaller than the maximum diameter of the recessed region. Correspondingly, an extension system is also provided in the present embodiment.

The expansion system is located on the optical path between the light source and the light homogenizing device for changing the optical path of the inner wall of the light source, thereby reducing the distance between the peripheral beam and the inner beam, so that the inner beam passes through the extended system The peripheral beam direction is extended such that the inner circumference beam is close to the peripheral light and the diameter of the light source does not change, thus avoiding the recessed area at the center of the homogenizing device.

Embodiments of the present invention also provide a projection apparatus including a light source system as described above. The projection device is an educational projector, a laser TV, a micro-projection or a cinema machine.

In summary, the light source system and the projection device of the present invention are not only low in cost, high in efficiency, but also uniform in illumination, and have a good user experience.

The above is only the embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformation of the present invention and the contents of the drawings may be directly or indirectly applied to other related technologies. The fields are all included in the scope of patent protection of the present invention.

Claims

A light source system, characterized in that the light source system comprises:

a light source for emitting source light, the source light comprising a plurality of beams parallel to each other;

a light homogenizing device, the source light is incident on a light homogenizing device for adjusting uniformity of the source light, the light homogenizing device is a double row microlens array, and the double row microlens array The center of the lens surface has a recessed area, the plurality of beams avoiding the recessed area on the double-row microlens array;

A relay module for concentrating and imaging the light beam.
The light source system according to claim 1, wherein a distance between two of the plurality of beams of the source light is greater than a maximum diameter of the recessed region.
The light source system of claim 2 wherein said light source system further comprises a compression system for reducing the diameter of said source light on an optical path between said light source and said light homogenizing means.
The light source system of claim 3 wherein said compression system uniformly reduces the distance between the beams.
A light source system according to claim 4, wherein said compression system includes at least one positive lens adjacent said light source and at least one negative lens adjacent said light homogenizing means for concentrating each The light beam is used to collimate each of the light beams.
The light source system according to claim 5, wherein said positive lens coincides with a main optical axis of said negative lens, and said positive lens and said negative lens are close to said uniform light The focus on one side of the device coincides.
The light source system according to claim 3, wherein said compression system is adapted to change an optical path of a peripheral beam of said source light such that a periphery of said light source is reduced in a first direction perpendicular to a central axis of said source light The distance between the beam and the inner beam of the source.
The light source system according to claim 7, wherein said compression system is further configured to change an optical path of a peripheral beam of said source light such that said source is reduced in a second direction perpendicular to a central axis of said source light The distance between the peripheral beam and the inner beam of the source.
The light source system according to claim 7, wherein said compression system comprises two sets of first reflecting means disposed opposite each other in a first direction on both sides of a source light central axis, said source light passing said first reflection The reflection of the device reduces the diameter in the first direction.
The light source system according to claim 9, wherein the compression system further comprises two sets of second reflecting means disposed opposite each other in a second direction on both sides of the central axis of the source light, the source light passing through the second The reflection of the reflecting means reduces the diameter in the second direction.
The light source system according to claim 1, wherein a distance between two of the plurality of beams of the source light is smaller than a maximum diameter of the recessed region.
The light source system according to claim 11, wherein said light source system further comprises an expansion system on an optical path between said light source and said light homogenizing means for changing an inner peripheral beam of said source light The light path is such that the inner peripheral light beam of the source light expands toward the peripheral beam of the light source, thereby avoiding the recessed region of the light homogenizing device.
The light source system according to claim 1, wherein the recessed portion has a diameter of 2 mm to 4 mm.
The light source system of claim 1 wherein said light homogenizing device Process by sol-gel process.
A projection apparatus, characterized in that the projection apparatus comprises the light source system according to any one of claims 1-14.